1. Field of the Invention
The present invention relates in general to protective shields for covering rotating cutting tools, and relates in particular to a spring-biased tubular safety shroud for use with hand-held motorized tools.
2. Description of Prior Developments
Shrouds, covers and shields have been used with various hand-held cutting tools for the purpose of protecting a user and others from unintentional inadvertent contact with a cutting bit or blade. Many of these shrouds provide only partial coverage of the blade, while others involve a complex assembly of multiple parts.
Although some prior shrouds provide full coverage of a blade, they must be manually opened and manually closed. With such a design, an operator can forget to close the shroud after use and thereby defeat the purpose of the shroud. Moreover, many conventional shrouds must be removed from a tool to allow an operator to change a bit or blade.
Accordingly, a need exists for a shroud or shield for a hand-held rotary tool wherein the shroud provides substantially complete coverage of a cutting blade or bit.
A further need exists for such a safety shroud which provides for the automatic closure of the shroud upon disengagement of the tool from a workpiece and/or release of a shroud actuator by a tool operator.
Another need exists for such a shroud which has relatively few parts and is of relatively simple construction.
Yet another need exists for such a shroud which allows for tool blade removal and replacement without removal of the shroud from the tool for at least selected tools.
The present invention has been developed to fulfill the needs noted above and therefore has as an object the provision of a safety shroud for substantially covering a cutting blade or bit on a rotary hand tool.
Another object of the invention is to provide a hand tool shroud which has a relatively simple construction, relatively few parts, and is easy to assemble and disassemble.
Yet another object of the invention is the provision of a hand tool shroud having a stationary portion and a movable portion which may be manually actuated to expose a cutting blade or bit.
Still another object of the invention is to provide a hand tool shroud having a spring-biased movable shroud portion which closes automatically upon release of a shroud actuator or upon disengagement of the shroud from a workpiece.
Another object of the invention is the provision of a hand tool shroud which allows for the removal and replacement of cutting blades and bits without removal of the shroud from the hand tool, for at least some tools.
These and other objects are met by the present invention which is directed to a hollow tubular shroud having a pair of opposed, nesting shroud portions. One shroud portion is stationary, while the other is movable into a nested position within the stationary portion to expose a cutting blade or bit. A conveniently located thumb lever is provided on the exterior of the movable shroud portion to allow an operator to manually open the shroud.
The movable shroud portion is biased into a normally closed position by a torsion spring. In this manner, when an operator releases the thumb lever and/or disengages the movable shroud from a workpiece, the torsion spring automatically closes the shroud. To improve visibility, the shroud can be formed of optically clear plastic such as a molded polycarbonate such as Lexan(copyright) plastic.
The aforementioned objects, features and advantages of the invention will, in part, be pointed out with particularity, and will, in part, become obvious from the following more detailed description of the invention, taken in conjunction with the accompanying drawings, which form an integral part thereof.